The first beta of io.js is about to be released in a couple of hours. If you can't wait, though, here is how you can take your existing node.js project and try it out on the io.js nightly.

Update: The release is out. You may now also use https://iojs.org/dist/latest/ in step 1 and then continue the same way.

1. Download the latest io.js nightly from https://iojs.org/download/nightly/ (Take those with "linux" or "darwin" in their name. They contain the prebuilt binaries.)
2. Extract the archive to let's say ~/iojs/
3. cd to the folder of your existing node.js project (preferably a copy of it)
4. Check with python --version that it points to version 2.6 or 2.7
5. Run ~/iojs/bin/npm rebuild to recompile packages with native code
6. Start your app with ~/iojs/bin/iojs <your main js file>
7. If everything works fine you have earned the badge! ![io.js supported](https://img.shields.io/badge/io.js-supported-green.svg?style=flat)

Let me know in the comments if you stumble upon some issues and I will update the steps accordingly.